Ladders for small boats, such as inflatables, dinghies, tenders, Jon boats, etc., are known as aids to a person in the water in climbing into the boat. A permanently mounted transom ladder is preferred because it is available when needed and offers the greatest stability and minimizes the chances of capsizing the craft.
Many small boats are fitted with ladders permanently attached to their transoms. These ladders usually have two vertical posts with rungs attached between them. Some hinge and rotate down into the water when in use and rotate up and out of the water for storage. Twelve or more inches of width along the transom is required for installation.
Similar two-post ladders are attachable to the side of a boat. The upper posts on some are curved to loop over the gunwale. Such ladders require legs that protrude against the side of the boat to hold them in near vertical position and will not work on pontoon or inflatable boats or boats with minimum freeboard as the bottom of the ladder swings under the boat when weight is applied. The same difficulty arises when using a rope or Jacobs ladder.
Removable ladders must be stored when the boat is underway or they may be lost. Such ladders are dangerous as they may not be accessible to a lone boater in the water.